jacobus



Sept. 24, l 92 9- D. s. JAcoBqs 1,729,260

STEAM BOILER Original Filed Sept. 14, 1923 4 Sheets-Sheet l r` Q A( "J AL f e Q i t; Y 1` e f INI/ENTOR..

9W ayu/M BY A TTORNEYS.

Sept- 24, 1929. D. s.lJAcOBUs 1,729,260

STEAM BOILELR Original Filed Sept. 14, 1923 4 Sheets-Sheet 2 INVENTOR.

A T TORNE YS,

Sept. 24, 1929.

D. S. JACOBUS STEAM BOILER Original Filed Sept. 14, 1923 4 Sheets-Sheet3 I Nl yEN TOR.

ATTORNEYS.

Sept. 24,

D. \s. JACOBUS Original Filed Sept. 14, 1925 4 Sheets-Sheet 4 PatentedSept. 24, 192%?? UNITED STATES PATENT time@ e E it:

`AVID S. JACOBUS, OF JERSEY CITY, NEW JERSEY, .ASSIGNOR TO. THE BABCOCK@c VJILCOK COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEYSTEAM BOILER `applicationl filed September 14, 1923, Serial No. 662,621.Renewed May-1, 1928.

present invention relates to steam boilers particularly of the typeadapted for operation at high pressures and will be best under-l stoodfrom the following description and thev pair of headers which may beused in theboiler shown in Fig. 1; Fig. 3 is a View similar to Fig. 2showing a modification; Fig. it is a section on the line 4-4 of Fig: 3;Fig. 5 is a section on the line 5 5 of Fig. 2; Fig. 6 is a section onthe line 6-6vof Fig.`2; Fig. 7 is an elevation of a part of a pair ofheaders showing still another modification; Fig. .8 is a section on theline 88 of Fig. 7; Fig. 9 is a section on the line 9-9 of Fig. 1l; Fig.l0 is a section onvthe line 10-10 of Fig. 9, and Fig. 11 is an elevationof a pair of headers, such as is shown in Figs. 2 and 3, showing amethod of closing thel space between them.

Like reference characters indicate like parts in the several views.

In the illustrative form of boiler shown in Fig. l, the water tubes 10are divided into two banks, the high ends of the water tubes beingconnected to uptake headers 11 and the downtake headers 12 being dividedinto two parts connected by nipples 13. The two lowermost rows of tubes.14 and '15 are of larger diameter than the tubes 10. Between the banksof water tubes is a superheaterl', a barile 17 extending transversely ofthe water tubes to ive the gases two passes Aacross the water tues anddirecting the gases to the spaces between the nipples 13 and to a gasoutlet 14Il leading to the upper end-of an eeonornizer 15a, from thelower end of which thegases pass to a flue 16. The transverse barile 17terminates atl an inclined baiile formed adjacent the superheaterheaders and ending adjacent the downtake headers 12.- A forced blastchain grate Stoker 18 is located beneath the furnace chamber 19. Thedown take headers 12 areconneeted to a transverse steam and water drum2() and theuptake headers 11 are similarly connected .through the pipes21. The drum v20 exemplifies a steam and Water separator which may beeither the single compartment illustrated or may also include aplurality of compartments. The connections between the separator and theend portions of the headers may be the direct form` of connection shown,or may be made through intermediate compartments if desired. The entirearrangement of boiler elements described above, forms a. unit, by whichterm I mean a self-contained boiler forming either a part or al1 of thesteam generating surface to which heat is applied.

It will be understood that the uptake and downtake headers are formed inasimilar manner, so that a'deseription of one of them will besufiieient. Preferably, in order to stand the high pressures for whichthe illustrative boiler is particularly adapted, I form the headers asseamless tubes, these tubes pref-v erably having a curved perimeter withone part of such perimeter curved on a relatively long radius so as togive a somewhat flattened portion in which the water tubes may beentered. AIn the speciiic form illustrated, the headers aresubstantially circular in crossseetion for the greater portionof theireir-v cumferenee, the portion formed with the long radius intersectingthe circular outline of the header. It will be obvious that such-asection is capable of standing heavy internal pressures, and, atthe sametime, provides a convenient tube surface so that the tubes may enter thesurface in groups with the tubes -normal to such surface or very nearlyso without undue bending of the ends of the tubes.

The tubes are preferably arranged in horizontal rows, as is usual inwater tube boilers, and preferably a plurality of the tubes of each rowenter each header. The headers are preferably spaced apart a distance atleast as great as the diameter of a water tube,

in order that a tube may be withdrawn between the headers. By bendingthe ends of some or all of the tubes as shown best in Fig. 6, the tubesmay be spaced across the boiler uniformly notwithstanding the4 spacebetween the headers and, moreover, by bending the ends as shown in Fig.6, the tubesin succeeding rows vertically may be stag gered relativelyto each other.' While the arrangement shown in Fig. 2 does-not produceuniform diagonal lanes between the ioc , enter a circular fitting ttubes as is usual in water tube boilers.` such true and uniformdiagonale may be obtained by slightly changing the vertical distances ofthe rows, if desired.

It is necessary to provide the headers with handhole openings which maybe closed in the usual manner wih fittings having internal seats, theseho es being provided so that tube cleaners may be inserted in theseveral tubes. In order not to weaken the header unduly, it is desirablethat there shall be as few of these handholes as possible and that theybe as small as possible, and for this` reason, I preferably arrange thehorizontal rowsjof tubes in pairs in which the vertical distance betweenthe rowsin each pa'rr is less than the vertical distance between ltherespective pairs. By this means, as shown in Fig. 2, for instance, asmall circular handhole 22 may be utilized to insert a cleaning tool inany une of the six tubes adjacent such handhol, and by bringing the rowsof tubes adj?` 'fit the handholes 22 relatively closetogetr. access toeach of this group of tubes be hadl through a much smaller hole thanwould otherwise be possible. Since, however, ithis not possible to ougha circular hole, if such fitting is to begeated internally of theheader, I elongate some of the handholes, as shown, for instance, at 23and, of course, provide a correspondingly elongated handhole fitting forsuch holes. As is well known, a fittingof this shape may be entered,such an elongated hole even though it is to be seated on the interior ofthe header and by providing these elongated handholes adjacent eachcircular handhole, I am enabled to enter the fitting for the next ad`jacent circular handhole through one of the elongated holes 23, theelongated hole being sufficiently close to the circular Yhole topermit acircular fitting to be passed through the eongated hole and then haveits end passe 'out through the circular opening.

With the tubes arranged as shown in Fig. 2, the middle tube of eachgroup of three cannot be removed and replaced without also cutting out`and replacingV one of the adja cent tubes, because there is -notsufficient distance between the rows to enable such middle tube to bepassed between rows and then out between the' headers. This difficultymay be obviated by arranging the rows as shown in' row to the spacebetween. the headers.

When the tubes are removed, they must be angled somewhat in orderytopass the end through the space between theheaders. The tubes beingsmall, the endslfmay be bent in this angling without materiallydisturbing the baille 17 through which the tubes pass. Preferably l makethe space around the tube in the baflle 17 somewhat larger than thediameter of' the tube to assist in this angling. By having a singlebaille, it is obvious that a tube hole lthrough the baffle need be onlyslightly larger-than the tube diameter and, moreover', by having asingle baffle, the possi bility of gas leakage through the tube hole inthe baffle is reduced to a minimium, because the transverse baffle actsmerely as a guide to direct the gases, the pressures on the oppositesides of the baffle being such that the gases have little or no tendencyto flow through the small `hpenings in the baffle. The gases in thefirst pass tend to rise rather than to fiow laterally, because cf thestack effect of this first pass, and the suction in the second pass nearthe bottom of the bafile may be less at the lighter loads than thesuction on the opposite side of the baffle in the first pass. Even atthe higher loads, the suction in the second pass is' not sufiicientlygreater vthan that in the first pass to draw any material amount ofgases through the small openings around the tubes in the bafile.

The two lowerinost rows of tubes 14 and `15 may be spaced either asshown in Fig. 2 or in Fig. In the latter figure, the lower most row iscomposed of a single tube for eaeh'headcr and the tubes of the row 15are entered in groups of two in each header. This provides a very widespace between the tubes 14C of the lowermost row and a less Vspace be.-tween the tubes l5 of the second row. In the arrangement shown in Fig.2, the Spacing between the rows of tubes 14 and 15 is uniform, the tubesin each row being entered singly and in pairs in adjacent headers. Ifdesired, as shown in Fig. 2, some of the small tubes 10 may be arrangedin a manner similar to the rows 14 and 150i Fig. 2.

In Figs. 7 and 8, I have shown an arrangement in which the headers 11are circular in cross-section and spaced apart at least the diameter oftube with the tubes 10 having their ends bent alternatively inoppositedirections in successive rows vertically so as t-ostagger the tubes,handhole fittings 24 being provided for openings opposite the ends ofeach tube. In the arrangement shown in Figs. 7 and 8, thetubes ff a rowdo not extend across the space between -a pair of tubes of adjacentrows.

Since the 4headers are spaced apart, it isy desirable toelose thisspace, and in Figs. 9, 10 and-11, I have shown a means to that end. Inthe form illustrated, lugs 25 are'formed on the header', as, forinstance, by autogenous welding, each lug being provided with a verticalslit v26 extending part way down through the lug and in 'each slit ispositioned a projection 27 on the edge of a plate 28' j spanning thespace between the headers, this plate preferably being curved as shownbest in Fig. 9, so that its edgespcontact with the walls of the headers,and, at the-same time,

so that slight relative movement between the headerswill not jam theplate 28, the curved edges of theplate in such case sliding aroundthecurved Wall of the header.

Preferably the closure is formed .of a plurality of plates 28 placed endto end with their ends overlapping and each plate supported on thebottom of a pair of lugs 25. Preferably each plate 28 is provided withan openino' through which cleaning tools may be inserte this openingbeing closed in the form illustrated by a slide plate 29 held againstplate 28 by a pair of guides 30.

It will be understood that thearrangement shown in the drawings ismerely illustrative' and that the embodiment of my invention may bewidely varied.l Certain fea# tures and forms of this invention are notclaimed herein, but are reserved for further divisional applications.

I claim:

1. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,each header having a cross section whose perimeter is curved and thefront part adjacent the tubes having a radius of curvature that islonger than the radius of curvature of the back part of said header, thetubes being arranged in horizontal rows with a plurality of tubes ineach row entering the front part ofeach header perpendicular to thesurface thereof.

2. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,each header having a cross section whose perimeter is curved and thefront part adjacent the tubes having a radius of curvature that islonger than the radius of curvature of the back part'of said header, thetubes being arranged in horizontal rows with a plurality of tubes ineach row entering the front part of each header, and the ends of thetubes being bent to stagger the tubes in adjacent rows vertically.

3. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,each header having a cross section whose perimeter is curved and thefront part `adjacent the tubes having a relatively long radius ofcurvature, the tubes being arranged in horizontal rows with a pluralityof tubes in each row entering the front part of each header, saidheaders being spaced apart a distance at least as great as the diameterof a tube and the ends of the tubes being bent to space the tubes ineach row uniformly across the boiler.

4. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers respectively.,

,each header having a cross section whose' perimeter is curved and thefront part adjacent the tubes having a relatively longy radius ofcurvature, the tubes being arranged in horizontal rows with a pluralityof tubes in each row -entering the front part of each header, saidheaders being spaced apart a distance at least as great as the diameterof a tube and the ends of the tubes being bent to space the tubes ineach row uniformly across the boiler and to stagger all of the tubes ineach row in relation to the adjacent rows vertically.

5. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,each header having a cross section whose perimeter is curved and thefront part adjacent the tubes having a 'relatively long radius ofcurvat/urehetubes being arranged in horizontal rows with a plurality ofthe lowermost rows formed of tubes of larger diameter an the remainderof the rows, a plurality of the-tubes in each row of smallerl diameterentering the front part of each header perpendicular to the surfacethereof.

6. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,the tubes being arranged in horizontal rows with a plurality of tubes ineach rov.l entering each header, and the horizontal rows being arrangedin pairs lvertically and said pairsI being spaced apart vertically adistance of at least a diameter of the tube".

7. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,the tubes being arranged in horizontal rows with a plurality of tubes ineach row entering each header, and the horizontal rowsl being arrangedin pairs vertically with the vertical distance between the pairs ofrowr. greater than between the rows of a pair.

' 8. A water tube boiler, having horizontally inclined Water tubes.connected at their en ls to uptake and downtake headers, respectively,the tubes being arranged in horizontal rowsl Witlr a plurality of tubesin each row enterI ing each header, and the horizontal rows beingarranged in pairs vertically with the vcrtical distance between the,pairs of rows greater thanl between the rows of a pair, each headerhaving a handhole opposite the ends of the tubes of each pair of rowsentering such header, some of said .handholes being circular and theremainder elongated with 'the long aXis vertical, each circular `holehaw ing an elongated hole adjacent it.

9. A Water tube boiler, having horizontally inclin'edwater tubesconnected at their ends` to uptake and' downtake headers, respecrtively,the tubes being arranged in horizontal rows and the headers being spacedapart a lll) row entering each header and the ends of thetubes beingbent to space the tubes in each row uniformly across the boiler and tostagger all of the tubes in each row in relation to the jacent rowsvertically.

11. A Water tube boiler, having horizontally inclined water tubesconnected at their ends 'to uptakel and downtake headers, respectively,the tubes being arranged in horizontal rows and the headers being spacedapart a distance at least as great as the diameter of a tube, aplurality of tubes in each lrow entering each header and the ends of thetubes being bent to space the tubes in each row uniformly across theboiler, the horizontal rows being arranged in pairs vertically with thevertical distance between adjacent pairs greater than the distancebetween the rows of a pair, each header having a handhole opposite theends of the tubes 'of each pairof rows entering the header.

12. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,the tubes being arranged in horizontal rows and the headers being spacedapart a distance at least as great as the diameter of a tube, aplurality of tubes in each row entering each header and the ends of thetubes being bent to space the tubes in each row uniformlyacross theboiler, the horizontal rows being arranged in airs'vertically with thevertical distance etween adjacent pairs greater than the distancebetween the rows of a pair, each header having a handhole opposite theends of the tubes ofeach pair of rows entering the header, some of saidhandholes being.c1rcular and the remainder elongated with the longax'isvertical, each circular hole having an elongated hole adjacent it.

. 13. A water tube boiler having horizontally inclined water tubesconnected at their-ends to uptake and downtake headers,respectively, thedowntake headers being formed in two parts with nipples connecting theparts, a transverse baille extending across the tubes to give the gasesan up-pass over one end of the tubes and a down-pass to the spacesbetween said nipples, said tubes being bent at their ends to enter saidheaders and the spaces in said baflle around the tubes. being largerthan the 'diameter f the tubes.

14. A water tube boiler, having horizontally inclined Water tubesconnected at their' ends touptake and downtakeheaders; respectively, thedowntake headers being formed in two parts with nipples connecting theparts,

'and the uptake headers being spaced apart a distance at least as greatas the diameter of a tube, a transverse baffle extending across thetubes to give the gases an up-pass over one end of thetubes and adown-pass to the spaces between said nipples, said tubes being bent attheir end'szto enter said headers and the spaces in said baflle'aroundthe tubes being larger than the diameter of the tubes and theftubeshaving sutlicient flexibility to perinit them to be withdrawn between apair of r '15. A water tube boiler, having horizontally inclined watertubes connected at their cnds to uptake and dow-ntake headers,respectively, said headers being spaced apart a distance of at least adiameter of a water tube,

and a closure for each of such spaces, coml tacting with and held'against the walls ot adjacent headers, the plate having openings atspaced intervals to permit the insertion o't cleaning tools, andclosures for said openings.

17. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,saidv headers boing spaced apart a distance of at least a diameter of awatcrtube, and a closure for each of such spaces, cornprising a metalplate extending across such space with its edges contacting with thewalls of adjacent headers and the plate having portions inserted invertical slits formed in projections on said headers.

18. A water tube boiler, having horizontally inclined water tubesconnected at their ends to uptake and downtake headers, respectively,said headers being spaced apart a distance. of'at least a diameter of awater tube, and a -closure for each of such spaces, com- Drising a metalplate extending across such space with its edges contacting with thewalls of adjacent headers and the plate havingr relatively shortprojecting portions on each edge engaging a slit in a lug formed in aheader.

19. A water tube boiler, having horizontally inclined' water tubesconnected at their ends to uptake and downtake headers, respectively,said headers being spaced apart a distance of at least a diameter of awater tube, and a closure for each of such spaces,

comprising a plurality of metal plates each extending across such spacewith its edges contacting with the walls of adjacent headers and withthe tops and bottoms ot adjacent plates overlapping, each plate having apair of oppositely disposed projections on its edges, each engaging aslit in a lug formed on a header with such projections resting on thebottom ofthe slit.

20. A water tube boiler having adjacent sections, each section havingwater tubes connecting a pair of vertically extending roundedA sectionheaders, the adjacent headers being spaced apart sufficiently to allowwithdrawal of a section, the tube nest of each section being of greaterWidth than the width of its header, the tubes in the sections beinguniformly spaced from side to side of the boiler, and the tubes in thelower part of the boiler being spaced apart a horizontal distancegreater than the horizontal distance between tubes in the upper partthereof.

21. A Water tube boiler having adjacent sections, each section havingwater tubes connecting a'pair of vertically extending rounded sectionheaders, the adjacent headers being spaced apart sufficiently to allowwithdrawal of a section7 the tube nest of each section being of greaterwidth than the width of its header, the tubes inthe sections beinguniformly spaced from side to side'of the boiler, the tubes in the lowerpart oi-the boiler being-spaced apart a horizontalA distance greaterthan the horizontal distance between tubes in the upper part thereof,and those in the lower part being of larger di ameter than those in theupper part.

22. A water tube boiler having adjacent sections, each section havingwater tubes connecting a pair of vertically extending rounded sectionheaders, the adjacent head ers being spaced apart suilicientl to allowwithdrawal of a sect-ion, the tu e nest of each section being of greaterwidth than the width of its header, and said headers having handholesaffording access to the tubes, and the tubes being bent at theirends topoint towards said handholes.

23. A water tube boiler having adjacent sections, each section havingwater tubes connecting a pair of vertically extending rounded sectionheaders,the adjacent headers being spaced apart suiieiently to allowwithdrawal of a section, the tube nest of each section being of greaterwidth than the width of its header, and the tubes being staggered in thedirection of gas flow.

24. In a heat transfer device, a plurality of sections arranged side byside, each section having a pair vof headers provided with walls havingsets of tube holes, tubes secured in said holes and connecting the twoheaders of each pair, at least some of said tubes being bent at theirends to enterthe holes in the header walls, the headers at each end ofgases, and the tubes contacted by the gases 2 later being spacedrelatively close together in said transverse direction.

25. In a heat transfer' device, a plurality oi sections arranged side byside, each section having a pair of headers provided with walls havingsets of tube holes, tubes secured in said holes and connecting the twoheaders of each pair, at least some of said tubes being bent at theirends to enter-the holes in the header walls, the headers at each end ofthe sections having a'series of longitudmally disposed openings givingaccess to the tubes, closures therefor, a water oompartment common to agroup of headers at` one end of thev sections, pipes connecting the endportions of said headers to said water compartment, and means causinghot gasesv to fiow across said tubes, the first tubes contacted by saidgases being of relatively large diameter and spaced apart a greaterdistance than tubes later contacted.

26. A water tube boiler unit comprising a plurality of sections arrangedside by Side, each section having a pair of headers with longitudinallyextending eircumfereniially' curved wall portions provided with sets ofholes each arranged in a circumferential band of said curved surface,tubes secured in said holes and connecting the two headers of each pair,at least some of said tubes being -bent at their ends to enter the holesin the curved walls, the headers at each end of t-he sections having alongitudinally disposed series of openings giving access to the tubes,closures therefor, a steam and water separator disposed above thelevelof one group of headers and arranged to have a water level intermediatethereof, and pipes connecting the end portions of both groups of headersto said separator, the pipes connectingl one group of headers to theseparator being adapted to conductiiuid from the separator to theheaders .and the pipes-connecting the other group of headers to theseparator being adapted to conduct fluid to the separator. l

27. YA water tube boiler unit comprising a plurality ot. sectionsarranged side by side, each section having a pair of headers withlongitudinally extending eircum'ferentially curved wall portionsprovided with sets of holes each arranged in a circumferential band ofsaid curved surface, tubes secured in said holes and connecting the twoheaders 0f each pair, at least some of said tubes being bent at theirends to enter the holes in the series of openings giving access toet-hetubes,

closures therefor, u steam and wat-er separator disposed above the levelof one group of headers and arranged to have a water level intermediatethereof, and pipes connecting the end portions of both groups of headersto said separator, the pipe-s connecting one group of headers to theseparator being adapted to conduct fluid vfrom .t-lie separator to theheaders and the pipes connectinoV the other group of headers to theseparator being ada ted to conduct fluid to the separator, the tu esilirows transverse to the headers being substantially uniformly spaced insaid rows.

28. A water tube boiler unit comprising a plurality of sectionsarrangedside by side, each section having a pair of headers with longitudinallyextending circiunferentially curved Wall portions provided with sets ofholes each arranged in a circumferential band of said curved surface,tubes secured in said holes and connecting the two headers of each pair,at least soine of said tubes being bent at their ends to enter the holesin the curved walls, the headers at each end of the sections having alongitudinally disposed series of openings giving access tothe tubes,closures therefor, a steam and water separator disposed above tlie levelof one. group of headers and arranged to have a Water level intermediatethereof, and pipes connecting the end portions of both groups of headersto said separator, the pipes connectingone group of headers to theseparator being adapted to conduct fiuid from the separator totheheaders and the pipes connecting the other group of headers to theseparator being adapted to conduct fluid to the separator, .the adjacentheaders being spa-ced apart a clear distance greater than a tubediameter. i 29. A wat-cr tube boiler unit comprising a plurality ofsections arranged side by side, each section having a pair of headersprovided with. Walls having sets of' tube holes, tubes se cured in saidholes and connecting the two headers of each pair, at least some of saidtubes being bent at their ends to enter .the holes in the header Walls,the headers at cach end of the sections having a longitudinally disposedseries of openings giving access to the tubes, closuresl therefor,vmeans causiii'g hot gases .to iow across said tubes, the spacing ofsaid tubes being substantially uniform across the` gas stream, a steamand water separator disposed above the level of one'group of headers and,arranged to have a water level intermedi ate thereof, pipcsconnectin gthe end portions of 'both groups of headers to said separator, thepipesconnecting one group of headers to the separator being adapted toconduct (luid from the separator to the headers,

and the pipes connecting the other group of hea dersto the separatorbeing adapted to conduct fluid to .the separator. Y

30. A water tube boiler unit comprising a plurality of sections arrangedside by side,

each section having a pair of headers with "i longitudinally :extendingcircuinferentially lcurved wall portions provided with sets vof holesleach arranged in a circumferential ba-nd of said curved surface, tubessecured in said Y holes and connecting the tivo headers of each d pair,at least some of said tubes being bent at their ends to enterv the holesin thecurved walls, the headers at each end of the sections having alongitudinally disposed series of openings giving access to the tubes,closures therefor, a--steam and water separator dis posed'above thelevel of one group of headers and arranged to have a Water levelintermediate thereof, and pipes connecting the end y portions ofbothgroups of headers to said separator, the pipes connecting. one group ofheaders to the separatorbeing adapted'to conduct fluid from theseparator to the headers and the pipes connecting ,the other group ofheaders to the separator being adapted to conduct fluid to theseparator, the tube nest connecting each pair of headers being Widercent headers.

3l. A water tube boiler un'iteomprising plurality of sections arrangedside by side, cach section having a plair oh'eaiders formed of seamlesstubes with o ng'itudinally extending circumferentially curvedWallportions ,a longitudinally disposed series of'openings giving accessto the tubes, closures therefor, a

steam and water separator common to a4 group of headers at one'end. ofthe sections, and pipes connecting the end portions of said headers tosaid steam and water separator.

32. A water tube boiler unit comprising a plurality of sections arrangedside by side,v each section having a pair of headers formed ofseamlesstubes with longitudinally extending circumferentally curvedwallportions provided withsets of holes each arranged 'in a circumferentialband of'said curved surface,

water tubes secured in said holes andconn'ectf ing the two headers ofeach painat least Sonie of said tubes being bent at their ends to'enterthe vholes in the curved walls, the headers at each end ofthe sectionshaving`a longitudi nally disposed series of openings .givingac- -cess tothe'tubes, closurestherefor, a steam and Water separator oinn'ionto agroup of headers at one end of the sections, and pipes connecting theend portions offsaid headers to said steam and water separator, each ofthan the distance betweenccnter lines of adj a- 'izo said headers havinga section whose perimeter includes curves Aof diierent radii, the

tubes entering the header along a surface having one of said radii andsubstantially perpendicular thereto.

33. .A Water tube boiler unit comprising a group of uptake headers and agroup of downtake headers7 both having longitudinally eX- tendingeireunlferentially curved wall por- 10 tions provided with sets ofholes, eaeh arranged in a circumferential band of said curved surface,tubes secured in said holes and Connecting the uptake and downtakeheaders, at least some of said tubes being bent at least one end toenter said holes, said headers having longitudinally disposed sets ofopenings giving access t-o the tubes, closures for said openings, asteam and water separator disposed above the level of one group ofheaders and arranged to have a Water level intermediate thereof, andpipes Connecting the end portions of both groups of headers to saidseparator, the pipes Connecting one group of headers to the separatorbeing adapted to conduct fluid from the separator to the headers and thepipes connecting the other group of headers to the separator beingadapted to conduct fluid to the separator.

DAVID S. J ACOBUS.

